Carburetor



Aug. l@

canBUas'rOR Filed Oct.

27, 1921 3 Sheets-Shut E etented Aug.` lil, 1926.

unire STATES rarer SMILES RAYYEELD, 0F GHiICAGO, ILLINS, ASSGNOR TO BEHEER MANUFATR- Iii! CQMPANL A CORPOHTION OFIILLINOIS.

CARBUBETOR.

Application led Oetober 27, 1922. Serial No. 510,708.

, This invention relates to a carburetor and particularly to a carburetor which has few moving parte and which supplies properly proportioned fuel mixture in the proper quantities Vto insure the eiicient operation of an internal combustion engine under all running conditions.

It is an object of this invention to provide 'a carburetor -Wherein means affording a movable Venturi chamber are connected by flexible connecting means with a plunger operating in a liquid dash pot and wherein said iexible coni-looting means acts to regulate the amount of fuel discharged through the :main nozzle in accordance with the movement of the Venturi chamber.

t is also an object ot this invention to provide a carburetor wherein a properly proportioned fuel mixture is introduced in- .20 to the mixture outlet chamber for purposes of idling and for' starting the motor.

It is a further object ot this invention to v provide a carburetor having manually operated means 'for controlling the introduction of an accurately' proportioned fuel mixture for starting purposes.' Y

lt is anotherobject of this invention to provide a carburetor having a compound nozzle and a variable air inlet and having means surrounding the nozzle inside the air inlet for dividing the fuel leaving the nozzle. c

It is an important object ot this invention to provide a carburetor having means for controlling and proportioninfz the Supply oi fuel and air to afford an economical iuel mixture for various operating conditions.

@ther and further important objects of this invention will be apparent from the disclosures in the, specitication and theaccompanvinnF drawings.

The invention (in a preferred form) is shown on' the drawings and hereinafter more fully described.

0n the drawings:

Figure l is a side elevation of a carburetor constructed according to the principles of this invention. s

Figure 2 is a top planview of the'carburetor.

Figure 3 is a. section on the line 3--3 of Figure l.

Figure fl is a fragmentary section on the line H of Figure 3.

II`igure 5 is a section on theline 5-5 yof Figure 1 with parte omitted.

Figure is an. enlarged detail section ot the nozzle taken at right angles to the section shown in Fig'. 3. l

Figure 7 is an enlarged fragmentary sec- 'tion on the line 7-7 o'f'Figure 9. with parts invention comprises a unitary casinfzy with a.

portion thereof affording,F a float chamber l while other portions thereof afford an air inlet chamber 2, a mixing chamber 3 and a dash pot cylinder or chamber 4. Formed on the upper end of the casing is an apera 'tured flange 5 which supports a mixture outlet casing 6. said mixture outlet 'casing 6 being'provided 'with a flange 7 restingo on the flange 5 and secured thereto by means of machine screws S engaged through apertures therein and' through the apertures in the flange 5. The mixture outlet casing 6 provided with a suitable Bange 9 whereby-a horizontal portion thereof may be connected to the intake manifold of an internal combustion engine on which the carburetor is mounted. andthe tiow of fuel mixture through said mixture. outlet casing is con-4 trolled by means of a hutteriiv throttle valve l0 which is mounted in the horizontal por-1.

tion of the casing. clearly shown inFigure 3. Liquid 'fuel is supplied from a source of fuel supply through a connection 11 to the float chamber l and the level of liquid fuel in said iloat chamber is maintained substantially constant by 'the usual Jfloat mechanisms mounted therein. Since these iioat mechanisms are Well known and since the one employed in this carburetor embodies no part of the present invention it has not been shown and will not be described in detail herein. Extending into the air inlet chamber 2 is a chambered boss gli l2 Which supportsI on its upper side a vertical tube 13 and which has a tube 14 ertendf ing therethrough and outwardly through the tube 13 to the upper end thereof where it is connected to said tube 13 by a threaded connection 15. A flange 16 is formed on entrance to the vpassage e7 therein. Communicating with the passage 44 is a passage del which in turn communicates with a vertical passage which opens into a recess 5l which lis ot larger diameter than said passage 50 and which is formed in a vertical boss 52 on the side of the carburetor casing. The tiow ot liquid fuel from the passage 50 into the recess 51 is regulated b v needle valve 53 which is axially mounted in said recess 51 and adapted to seat in the upper edge ot' the passage 50, Said needle valve 53 is slidably mounted in a plug 54 secured in the boss 52 at the upper end of the recess 51 and engaged between the inner side of said plug 54 and a collar 55 mounted on the needle valve near the lower end thereof is a helical spring 55a which acts to normally maintain said valve seated in the upper end or" the passage 50 to regulate the flow of liquid fuel therethrough. yAdjustment of the needle Valve 53 is attorded by the engagement of a threaded portion 5G thereof with a block 57 engaged thereon above said plug. Said block 57 is' held from rotation relative to the needlev valve by means which will be described hereinafter and the needle valve is locked in adjusted position relative to said block by means ot a spring-pressed detent 58 mounted therein and engaging a ribbed adjusting nut 59 secured to the upper end of the needle valve.

Leading from the lower end of the recess 5l is a passage 60 whichv communicates with a passagel leading into `the well 17 and consequently a limited supply of liquid fuel is supplied to said wellfrom the recess 5l through said. passages. Communicating with the passage 6l and extending upwardly therefrom is a passage 62 which is formed in an integral boss 63 on the outside of the carburetor casing and said passage 62 extends upwardly into the flange 7 on the casing 6 where it communicates with a tube 64 extending transversely across the inger end of said casing. l Said tube till is provided with an aperture 65 whereby air may enter the same from the mixing chamber 3 Iand a plug 66 in the end of said tube having a restricted aperture 67 therein affords an auxiliary nozzle which discharges a fuel mixture into a passage 68 which is formed in and which communicates with the interior of said casing outside the throttle valve 10 by means ot passages 69, 70 and 71 which are shown in dotted lilies in Figure 3. In order that the mixture of liquid t'uel and air 'for idling the engine may be properly proportioncc an air bleed aperture 72 is formed in the boss G3 opening into the passage 62 near the. upper end thereof.

Means are provided for lifting `the needle valve 53 away from its seat in the upper end of the-passage 50 and for closing the air bleed aperture 72 in order to supply a rich mixture for starting the engine on which the carburetor is mounted. For this purpose, a lever 73 is rotatably mounted on the outside ofthe boss 63 directly beneath the air bleed aperture 72 and mounted on the inside tace ot said lever 7-3 Vand rotatable therewith is an eccentric cam 74 which is adapted to engage the under sidevof a lever v7F which is pivotally mounted on the cai-,

buretor casing and the outer end of which is engaged in a recess in the under side of the block 57 to litt said block and the needleV tated by .securinglr a suitable connection such f as a flexible rodor Bowden wire to the terminal 7G thereon and for conveniencev in guiding this connection,` a guiding boss 77 is provided on the float chamber l. The return rotation of the lever 73 is limited by the engagementof a boss 78 on saidV lever with a stop 79 on the outside ofthe boss 52. The? operation of the throttle valve 10 is controlled by an adjustable 'lever 80 vwhich is secured to the outer end of the shaft on whirh the same is pivoted and which is adapted to be adjusted to limit the amount of closing movement of the Valve. In order thatithe float chamber l may be conveniently drained, a suitahledrain valve 8l is providadA A suitable fitting 82 is also provided whereby a. connection with any vacuum operated installation as a fuel supply system may be made.

The operation is as follows:

The'. tubes 13 and 14 aitord a compound les nozzle whereby liquid tuel is introduced into the Venturil chamber 22 where it is mixed with the air flowing therethrough and conducted into the mixing' chamber 3 lnd out-l wardly through the casing 6 past t' e throt tlc valve 10 to the intake manifold ot the engine. Fuel supplied from the well 17 is discharged through the apertures 19 and acts to provide a supply tor operation of the engine at intermediate speeds and also to supply additional fuel when it is desired to rapidly accelerate vthe engine. The main fuel feed at higher speed is provided by the tube 14 which forms the interior of the compound nozzle and as the/speed increases and the member 20 is lifted the metering pin 28 is, of course, lifted, enlarging the opening'in .the upper end of said tube, and more liquid fuel is'allowed to vbe drawn therefrom to mix with the additional quantities of air which pass through the carburetor due tothe lifting of said member Ilo of course,l passes putvvardly through the apertures 19 in they nozzle 1S, while the fuel leaving the tube'll is discharged directly from the end of said tube and in each-case this fuel necessarily Apasses outwardly into i the Venturich :aber 22 through the screen 43 which aids materially in the breaking up and atomization thereof. ln view of the fact that the supply of liquid fuel to the welll? is restricted by the needle valve 53, it is apparent that said well will act to supply only a limited amount of fuel such. as is demanded for purposes oi rapid acceleration and that the fuel supply therefrom will cease upon the attainment of the increased speed, the fuel for normal operation ut such speeds being,r 'supplied through the main nozzle, i. e., the tube le. The well ll' also provides a source of liquid fuel suppl if which furnishes the limited amount of fuel required to keep the engine running when the throttle valve l() is closed. .ll/'hen the engine idling` fuel is drawn upwardly from said Well 'i7 through the passages 6l and 62, air being bled into the aperture T2 entering; into the passage 62, and from said passage 62 fuel is led through the tube 6l' where additional air is introduced through the bleed aperture '65, the consequent idling` mixture being discharged into the passage 68 through the nozzle which is ailorded by the aperture 6'? in the plug 645. From the passage 68, fuel mixture for idlinnT purposes is delivered through the passages GS), 70 and 71 to the interior of the casing 6 outside the throttle valve l0.

The needle valve 53 may of course be adjusted to vary the amount of fuel which is allowed to enter the well 17 by rotating the ribbed adjustingr nut 59. Since the amount of fuel entering the 'Well 17 may be accurately regulated and since the air bleed apertures 72 and 6o are designed to introduce the proper quantity of air into the fuel which is supplied for idling purposes, it is apparent that the correct mixture for .idling the engine will be supplied atall times,

By operating the lever 73, the needle valve 53 may beraised away from its seat to increase the fuel supplied to the Well 17 and since this operation of the lever 73 also moves the rlever 75 to close the air bleed ap erture 72fa` correctly proportioned rich'fuel mixture Yfor starting the engine willbe supplied to a pointposterior to the throttle valve through the passages 6l, 62 and 64, caca, 7o, 7i,

All of the parts of the carburetor of this` invention are easily accessible for adjustment and repair. and since there are few moving parts, there is little likelihood of the carburetor getting out of order. Access'to the dash pot, chamber 4 ma be had by reu moving the closure 39 is threaded on ing pin. is assured, any flooding from the,

main nozzle of the carburetor under starting conditions is avoided. rl"he piston 82 in the dash pot chamber 4 acts to regulate the upward movement of the member 20 and since the metering; pin 28 act-s to allow the main nozzle, i. e. the tube il, to discharge more fuel as said member moves upwardly,

it is apparent that the fuel mixture discharged from said main nozzle Willbe properly proportioned at. all times., apparent from the that this invention provides a carburetor which supplies an economical properly proportioned fuel mixture for all running conditions, which `will not leak when the engine is not running, and which possesses few moving parts and is consequently not liable to get out of order.

l am a vare that numerous details of construction may be varied through a Wide range Without departing; from the principles of this invention, and l therefore do ,not purpose limiting the patent granted otherwise than necessitated by the prior art.

l claim as my invention:

- l. In a carburetor, a

a dash pot chamber communicating therewith, a mixing chamber, a nozzle opening into the mixing chamber and-,communicating With the dash pot chamber, a casing allording a Venturi chamber slidably mounted in the mixing chamber and surrounding the nozzle, a metering pin connected to said casing and adapted opening in said nozzle, a piston in the dash pot chamber, and a flexible Wire connection between the metering pin and said piston.'

- 2. In a carburetor, a fuel supply chamber, a dash pot chamber communicating therewith, a mixing chamber, a nozzle opening into the ymixing chamber and communicating with the dashpot chamber, a casing ailorclinsr` a Venturi chamber slidably mounted in the mixing chamberl and surrounding the nozzle, means connected to said casing for controlling the fuel discharged from the nozzle, a piston in the dash pot chamber, and

lt will be foregoing specitication' fuel supply chamber,`

to vary the area of the a llezible Wire connection between the-fuel sages connecting the sul ply chamber With the nozzle outlets, a connection between' one of said fuel passages and the fuel outlet chamber outside the throttle valve, means for admitting` uill to saidA connection, and means for .increasing the amount oi -fuel :Hou-ing;- thro'ugh said passage and simultm neously decreasing' the amount of air adinitterll to said connection.

4. In a carburetor, a fuel supply chamber, fuel outlet Chamber, a throttle Valve therein. a compoundnozzle, separate fuel 'pas` sages connecting the supply chamber with the nozzle outlets, a conneenon between the fuel outlet vchamber and the upper (me of said fuel passages outside the -throttle valve, means for admitting air to' said connection, and cam-controlled manually operated means for increasing the amount of fuel permittedto flow through said passagel and si-v multaneously decreasing the amount of air admitted to said connection.

Inv testimony whereof I have hereunto subscribed my name. Y

CHRLEs L. RAYFIELD. 

